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U. S. DEPARTMENT OF AGRICULTURE. 

BUREAU OF PLANT INDUSTRY— BULLETIN NO. Ill, PART IL 

^K B. T. GALLOWAY, (hi)/ of Tiureau. 



THE FIBEIIS OF LONG-STAPLE 
UPLAND COTTONS. 



H. A.^ALLARD, 
Scientific Assistant, Cotton Breeding Investigations. 



Issued Septembeb 9, 1901 




WASHINGTON: 

GOVERNMENT PllINTING OFFICE. 



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C N T H N T S 



Pace. 

rniforinity of cotton fibers 5 

Ai>|>arent lack of uniformity and its occurrence 5 

The true nature of the longer fibers 6 

lU-u 

3 



ILLUSTRATIONS 



PLATES. 

Page. 
Plate I. Cotton seeds with fibers attached. A and B. — ■Cotton seeds with 
fibers combed out to show uniformity and nonuniformity in the 
length of the fibers. C. — Lock of Griffin cotton stretched so as 

to show points of origin of longer fibers 4 

II. Seeds of cotton combed out to show the so-called longer fibers. 

A. — Columbia variety. B. — Grifiin variety 4 

TEXT FIGURES. 

Fig. 1. Single cotton fiber? from the so-called longer group of fibers 6 

2. A few extra-long cotton fibers, showing two fibers united 6 

3. Cotton fibers tied together, very much magnified 7 

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4 



Bui. 1 1 I , Pt. II, Bureau of Plant Industry, U. S. Dept. of Agriculture. 



Plate I. 




Bui. 1 1 1, Pt, II, Bureau of Plant Industry, U. S. Dept. of Agriculture. 



Plate II. 




Seeds of Cotton Combed Out to Show the So-called Longer Fibers. 
yl.— Culuiubiii vHiioly. i;.— Giill'm variety. 



B. I'. I.— m"). 



THE FIBERS OF LONG-STAPLE UPLAND 

COTTONS. 



UNIFORMITY OF COTTON FIBERS. 

In investij^ations in cotton breeding where an improvement in cer- 
tain lint characters is desired several factors must be carefully consid- 
ered. Among these, some of the most important are tinoness of lint, 
the relative 3'ield of lint to the total yield of seed cotton, and the uni- 
formity of length of all the fibers when properly combed out and 
examined. The la-st character, uniformity of length, is a most impor- 
tant one and has much to do with subsequent waste and the produc- 
tion of good yarns in the process of manufacture. 

On Plate I are illustrations of cotton seeds with fibers combed out 
to show uniformity and nonuniforniity in the length of the fibers. 
The seeds to the left (A) show very poor uniformity and are of the 
"butterfly''' type, as they are commonly called. In marked contrast, 
the seeds to the right (B) show excellent uniformity as a result of 
several generations of careful selection. 

APPARENT LACK OF UNIFORMITY AND ITS OCCURRENCE. 

There is an apparent lack of uniformity which deserves consider- 
able attention from the standpoint of cotton growers and breeders. 
Plate II illustrates this character, although it is more striUdngly 
brought out in the operation of detaching the seed from the lock. 
From the illustration there would appear to be a great lack of uni- 
formity, due to a group of fibers about twice the length of th(^ geneml 
covering. This group ari.ses from the center of the main l)ody of 
fil)ers or, often, from those having a point of attachment near the 
larger end of tin' seed. This character is usually as.sociated with the 
liner, more crinkly types of long-staple cottons, such as the tin(>. long- 
linted Egyptian and Sea Island varieties and the long-staple Tpland 
varieties- Griftin, Allen, Cook, etc. It is a character which becomes 
more apparent as a variety is being rigidly selected generation 
after generation for finer, longer staple. This has l)een well illus- 
trated in the improvement of the lint characters of the Hussell 
variety and, to some extent, the .lones variety. The orginal condition 

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THE FIBERS OF LONG-STAPLE UPLAND COTTONS. 




Fig. 1.— Single cotton fibers from 
the so-called longer group of 
fibers. 



of both of these varieties is remarkably free from this so-called longer 
group of fibers. In the case of the greatly improved Russell strain, 
which has become distinctive enough in good lint characters and yield 
to be designated as a new variety — the so-called Columbia cotton — 
these longer fibers are evident to a remarkable degree. 

THE TRUE NATURE OF THE LONGER FIBEl^S. 

It has been more or less the rule with cotton breeders and cotton 
growers acquainted with the requisites of desirable lint characters to 
regard these extra-long fibers as an unfavorable feature. In this light 
they meant a variation toward nonuniformity. In the work of selec- 
tion, to avoid as much as possible a perpetuation of this sort of varia- 
tion, plants showing this character most markedly were regarded with 

suspicion and later even discarded, although 
in other respects they were among the best in 
the field. 

A careful examination leads to the conclusion 
that these fibers should be regarded in a wholl}'^ 
different light. They are not longer Jihers aS 
they have heen generally considered^ hut are 
caused hy more or less curling and interweaving ^ 
which results in the pulling out of fibers from 
adjacent seeds. 

In the ordinary manner of stretching the locks to determine the 
drag, the fibers are slowly separated and drawn out, and at those points 
of greatest binding, as shown in Plate I, C, «, ^, and e, the groups of 
longer fibers appear to rise. If, now, a single seed is selected and 
detached from the rest and the entire group of fibers loosened from 
its attachment to the seed 



coat in the neighborhood of 
the longer groups, one can 
with fine forceps draw these 
fibers out carefully and com- 
pare their length with those 
of the rest of the seed. 

In many instances the sin- 
gle fibers now readily sepa- 
rate, since the tension of 
pulling has ceased. Several of these single fibers are shown in figure 1. 
In some instances fibers nearly twice the normal length are drawn out. 
Oftentimes with the naked eye the point of union or tying may be 
discerned by the tiny loose ends, as is shown in figure 2. In other 
cases, however, this i)oint of union is so intimate that only u iiigh 
microscopic power can make it evident. Figure 3 illustrates various 

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2.— A few extra-long cotton fibers, showing two 
fibers united. 



TBK TRUE NATURE OF THE LONGER FIBERS. 



degrees of this tyiuj^ or ciaiiiio- together, as seen when grcatl}- mag- 
nified. In figures 1 and 2 single and united fibers, respeotivel}', of 
natural length arc shown, hut the diameters are of nccossitv much 
greater than normal, owing to tiic exceeding fineness of the fibers. 

The drag of cottons showing the longer fi})ers previously described 
gives a more extended, elastic tension than is manifest among the 
short-staplo varieties. It is probable that breeders may find this 
character a useful one in indicating a tendency toward increased 
length, fineness, and crinkliness of staple in the individuals in which 
it occurs most noticeal)ly — an indication of better spinnini;- riualit}'. 

It is important that 
l)reeders and grow- 
ers of 1 o n g - s t a p 1 e 
cottons should know 
that these apparently 
longer fibers are no 
indication of true 
lack of uniformity. 
The presence of these 
fibers in the long- 
staple Upland varie- 
ties has (juite univer- 
sally led to the erro- 
neous belief that such 
cottons arc rather 
inf(M-ior in uniformit\' as regards length of fibers. The Griffin cotton, 
in particular, recognized in other respects as the best long-staple 
Upland cotton grown, has always l)een descril)ed as decidedly unsatis- 
factory so far as uniformity in length of staple is concerned, since the 
drawing out of fibers from adjacent seed is a marked characteristic of 
this variety-. 

A knowledge of the true nature of these longer fibers will clear the 
reputation of some of the l)est long-staple Upland varieties of a seri- 
ous fault hitherto wrongly attributed to them by all breeders and 
irrowers. 




Fi<;. 3. — Cotton fibers tied together, very mueh niiigiiiMed. 



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